BACKGROUND OF THE INVENTION
[0001] The present invention relates to a decorative sheet which comprises a decorative
layer which contains CaCO
3 as bonding ingredient, and a base sheet, and particularly to a decorative sheet which
provides opacifying properties over unevenness of the surface of a wall, a column
and a ceiling on which the decorative sheet is pasted, the decorative sheet being
not peeled off the surface, gaps in seams being effectively prevented after a plurality
of decorative sheets are continuously attached.
[0002] To finish walls, columns and ceilings made of CaSiO
3 boards and gypsum boards, polyvinyl chloride wall papers which can be easily constructed
and are inexpensive are widely used, but the finished surface to which the wall papers
are attached is not permeable, and condensation on the surface causes mold and peeling
of the wall papers, which is disadvantageous. Recently, the wall papers and adhesives
used for the attachment generates toxic volatile ingredients to cause various health
hazards.
[0003] Instead of the wall papers, wet finishing material such as plaster which is permeable
and does not generate toxic substance is used, but it takes a lot of time to solidify
the wet finishing material to increase a term of construction. Also, finishing is
variable depending on plasterer's skill. Lack of excellent plasterers has become serious
and it does not meet with the need.
[0004] The inventors suggested a decorative sheet having a decorative layer which contains
CaCO
3 that is a main ingredient of plaster on the surface of a base sheet to provide a
design that is very similar to plaster finishing, as disclosed in International Pub.
No.WO98/1296
[0005] Walls are covered with the decorative sheets to provide excellent function and good
design. The base sheet includes papers that have high strength such as original papers
for gypsum board to prevent breakage during and after manufacturing of the decorative
sheets.
[0006] To construct large area walls using the decorative sheets, there is a method of putting
up a plurality of decorative sheets:
(a) Adjacent decorative sheets are overlapped at the ends and pasted.
(b) The overlapped portion of the decorative sheets is cut by a cutter to provide
pasting of the decorative sheets without gap at the seams.
[0007] However, the decorative sheet in which the base layer comprises a gypsum board original
paper provides opacifying properties over unevenness of the decorative surface. When
the base sheet is thickened, the seam is opened with drying of paste to form a gap
or is likely to peel off by curling the ends owing to a long-term use.
[0008] The inventors have carefully studied solution of the disadvantages. It has been found
that, by thickening the base sheet to increase opacifying properties of the decorative
sheet, strength is increased and that the decorative layer which has good stability
in size is shrunk with shrinkage of the base sheet and portions that do not follow
the shrinkage are peeled off by curling, because change in size during drying is controlled
by high strength base sheet during moisturizing when high strength base sheet is used.
Based on such knowledge, as a result of further study, a base sheet that is thick
but has relative low strength can control stability in size of the decorative layer
to provide a high stable decorative sheet against change in moisture after attachment,
so that the inventors completed the present invention.
SUMMARY OF THE INVENTION
[0009] It is an object of the present invention to provide a decorative sheet in which a
base sheet is thickened to provide opacifying properties over unevenness of the decorative
surface, change in size after pasting to the decorative surface preventing peeling
off and a gap in the seam effectively for a long time.
[0010] To achieve the object, the inventors studied the material and found the following.
To provide opacifying properties of the decorative sheet, the thicker the base sheet
becomes, the higher its strength becomes. When such high strength base sheet made
of papers is used, change in size during moisturizing or drying is controlled by the
high-strength base sheet. The decorative layer that has good stability in size is
shrunk and parts that do not follow the shrinkage are curled and peeled off. As further
study based on the knowledge, thick but relatively low-tensile-strength base sheet
can control stability in size of the decorative layer. High stability decorative sheet
is obtained against change in moisturization after attachment.
[0011] The present invention provides a decorative sheet which comprises laminated material
which comprises a decorative layer which contains CaCO
3 as bonding ingredient and a base sheet, said base sheet having thickness of 120 to
300 µm tensile strength being 1.5 to 7 kN/m.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] The features and advantages of the invention will become more apparent from the following
description with respect to embodiments which are shown in appended drawing wherein:
Figure is a perspective view of a decorative sheet according to the present invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0013] In the present invention, a decorative sheet contains calcium carbonate (CaCO
3), as bonding ingredient, formed by reaction of a mixture of calcium hydroxide and
water with CO
2.
[0014] Carbonation of calcium hydroxide proceeds rapidly to about 50 % of reaction rate,
and thereafter slowly. Function as bonding ingredient exhibits sufficient advantages
when reaction rate of carbonation exceeds about 50 %. CaCO
3 in the decorative layer of the present invention contains what the reaction rate
becomes more than 50 %, and especially what exceeds about 60 % is preferable.
[0015] Ca(OH)
2 is available as industrial slaked lime, plaster, and dolomite plaster.
[0016] The decorative sheet which contains CaCO
3 as bonding ingredient preferably has surface hardness of more than 45 degree and
pencil hardness of more than B. The decorative layer which has such hardness can be
formed by laminating a protective sheet on the surface and hardening them. The decorative
layer improves scratch resistance remarkably and is suitable for the invention.
[0017] Various additives may be added to the decorative layer depending on use of constructive
material. The additives include solid ingredient of aqueous emulsion, fibers, inorganic
thin bone material, active microparticles and pigments.
[0018] The solid ingredient of the aqueous emulsion increases not only toughness of the
decorative layer, but also bonding strength between the decorative layer and base
sheet with peeling strength between the decorative layer and an air-permeable protective
sheet. By mixing solid ingredient suitably in the aqueous emulsion, it is possible
and suitable to adjust peeling/bonding strength of the decorative layer and permeable
protective sheet within the range.
[0019] The aqueous emulsion may be an emulsion in which monomer, oligomer and polymer thereof
are dispersed. The aqueous emulsion includes synthesized high-molecular emulsion of
acrylic resin, vinyl acetate and stylene/butadiene rubber. When hardened body of CaCO
3 is formed, the medium in the aqueous emulsion is evaporated and at least part of
the solid ingredient exists in the hardened material of CaCO
3.
[0020] The fibers include known fibers which can be mixed into the decorative layer. For
example, there are glass fibers, vinylon fibers, polypropylene fibers, polyester fibers,
polyethylene terephtalate fibers, acrylic fibers, alamide fibers, carbon fibers and
metal fibers. As to shape of the fibers, short fibers, long fibers, woven fabrics
and non-woven fabrics can be used. Especially, the short fibers are especially advantageous
to increase toughness and cutting properties and suitably used. The length and diameter
of the short fibers are not especially limited. But preferably the length may be 1
to 10 mm, especially 2 to 6 mm, and the diameter may be 5 to 50 µm, especially 10
to 30 µm to increase toughness of the decorative layer and to provide excellent cutting
properties.
[0021] The inorganic thin bone material includes CaCO
3 (that does not act as bonding ingredient) having average diameter of 0.001 to 2 mm;
quartz sand; cold water sand; mica; sesode quarts sand; sesode mica; ceramic sand;
glass beads perlites. When the base material comprises a sheet, the average diameter
may be preferably 0.003 to 1.0 mm, and when the base material comprises a sheet, and
when the decorative layer does not substantially contain fibers and has thickness
of 0.1 to 1 mm, the average particle diameter may be preferably 0.003 to 0.5 mm. Furthermore,
the active particle includes blast furnace water granulated slag; fly ash and silica
fume having average particle diameter of 0.1 to 50 µm.
[0022] The pigments include metal oxides such as iron oxide, titanium oxide and chromium
oxide having average diameter of 0.5 to 50 µm, and stone powders.
[0023] The other additives include organic miscible material such as paraffin; calcium stearate
and magnesium stearate; silicone oil or silicone resins which mainly contain polysiloxane
in which dimethyl polysiloxane and its methyl are partially replaced with hydrogen,
phenyl, alkyl, mercapto, vinyl, cianoalkyl or fluoroalkyl; organoalkoxy silane such
as methyltrimethoxy silane; ethyl trimethoxy silane, dimethyldimethoxy silane, diethyldimethoxy
silane, butyltrimethoxy silane, hexyltrimethoxy silane, heptyltrimethoxy silane, octyltrimethoxy
silane, dihexyldimethoxy silane, diheptyldimethoxy silane, and trihexylmethoxy silane.
[0024] The content of the additive is not limited. Generally the following ratio is preferable
in the decorative layer. The ratio is calculated by the condition where the total
amount of Ca(OH)
2 is carbonated to convert CaCO
3.
[0025] The aqueous emulsion may be added at 0.5 to 18 % by weight, preferably 2 to 15 %
by weight under conversion to solid ingredient so as to increase toughness of the
decorative layer, bonding strength between the decorative layer and the base material,
and peeling strength between the decorative layer and the sheet.
[0026] The fibers may be preferably added at 0.1 to 5 % by weight in case of short fibers,
but in case that the base material comprises a sheet and thickness of the decorative
layer is 0.1 to 1 mm, flexibility of constructive material can be substantially assured
without adding fibers.
[0027] The inorganic thin bone material may be added at less than 70 % by weight, preferably
less than 60 % by weight. The pigment of less than 5 % by weight can be used without
problem.
[0028] As other additives, organic miscible agent, silicone oil, silicone resin and organoalcoxy
silane are advantageous to increase waterproofness, freezing-fusion resistance, chemical
resistance and weather resistance, and may be added at 0.05 to 2 % by weight in the
decorative layer of CaCO
3.
[0029] In the present invention, when any of the additives are added to the decorative layer,
CaCO
3 (calculated at 100 % carbonated condition of Ca(OH)
2 similar to the above) which acts as bonding agent may be added at more than 10 %
by weight, preferably 25 % by weight, more preferably 30 % by weight so as to imitate
design on the surface of the decorative layer to plaster finishing.
In the present invention, the decorative layer which contains CaCO
3 as bonding ingredient may preferably have thickness of 100 to 2000 µm, preferably
100 to 1000 µm so as to increase bending resistance by laminating a permeable protective
sheet (will be described later) at the above peeling strength without substantially
containing fibers.
In the present invention, the decorative layer in unhardened slurry can be applied
on one surface to harden the base sheet and hardened to laminate on the base sheet.
[0030] The features of the present invention is that the base sheet has tensile strength
of 1.5 to 7 kN/m, preferably 3 to 5 kN/m compared with a known base sheet which has
tensile strength of more than 10 kN/m for the purpose of opacifying unevenness of
the surface. If the tensile strength of the base sheet is more than 7kN/m, size stability
of the decorative sheet is controlled by the base sheet after attachment, so that
a seam is opened gradually with drying after attachment of the decorative sheet with
paste and a gap can be seen. The gap that exceeds 0.05 mm defaces seam of the decorative
sheet after construction,
[0031] On the contrary, if tensile strength of the base sheet is less than 1.5 N/m, strength
in manufacturing is not sufficient, and the decorative sheet cannot be stably manufactured.
[0032] In the specification, tensile strength of the base sheet is determined in the strongest
direction, and when the base sheet is continuously manufactured, it is longitudinal
tensile strength in manufacturing.
[0033] In the present invention thickness of the base sheet having the above tensile strength
is 120 to 300 µm, especially 130 to 180 µm so as to increase adhesiveness when it
is pasted to a wall, to form a stable finishing surface. Thickness of a known base
sheet was at most 100 µm.
[0034] If the base sheet is too thin, it becomes difficult to absorb unevenness of the wall
surface on which the decorative sheet is attached, and the decorative layer is partially
floated to cause cracks. If the base sheet is too thick, the decorative layer becomes
unstable after attachment, and cracks are likely to occur when the surface is pressed.
[0035] It is the features of the present invention that the base sheet has specific thickness
and relatively low tensile strength, which has been suggested for the first time by
the present invention.
[0036] In the present invention, the base sheet is not especially limited if it meets with
the above conditions, and water elongation is preferably less than 1 % and more preferably
less than 0.8 % as mentioned below. If water elongation is too high, unhardened decorative
layer that has insufficient strength is deformed such as curling by shrinkage of the
base sheet to generate trouble in manufacturing. Such water elongation under the above
range is preferable.
[0037] Air permeability is preferably less than 10 sec., especially 3 to 8 sec. for manufacturing.
[0038] The above water elongation and air permeability are determined by TAPPI-No.27-B and
JIS-P8117.
[0039] In the present invention, the base sheet may be made of papers so as to fit the unhardened
slurry and increase between the decorative layer and the base sheet. The decorative
sheet according to the present invention is manufactured by applying unhardened slurry
as mentioned above, and the base sheet on which the decorative sheet is laminated
may preferably fit with the slurry rapidly from application of the unhardened slurry
to hardening step so as to prevent creases on the base sheet during manufacturing.
[0040] In particular, it is preferable to use papers in which inorganic fillers such as
CaCO
3 and Al(OH)
3 are contained at a lot of amount, such as 30 to 90 % by weight, preferably 40 to
70 % by weight to decrease combustibility.
[0041] It is most preferable to use CaCO
3 as inorganic filler.
[0042] Suitable base sheets that comply with the above conditions are OK Cosmo CA 135 and
OK Cosmo CA 100 manufactured by Oji Paper Co., Ltd.
[0043] As shown in Figure, in the decorative sheet according to the present invention, a
peerable air-permeable protective sheet 3 is laminated on the surface of the decorative
layer 2 which contains CaCO
3 as bonding ingredient on the surface of the base sheet 1 so as to protect the decorative
layer easily and prevent cracking effectively by bending in handling.
[0044] Peel strength of the air-permeable protective sheet laminated on the decorative sheet
may be preferably 200 to 400 mN, more preferably 800 to 2500 mN.
[0045] Peel strength in the present invention is determined using a sample having width
of 25 mm under the condition of 300 mm/min depending on 180°peel/bonding strength
test of JIS-K6854.
[0046] In the present invention, the air-permeable protective sheet has substantially uniform
air-permeability on the whole surface and does not give bad effect under the following
condition. Significant deformation and deterioration do not occur by contact with
mixture of Ca(OH)
3 and water of unhardened slurry of the decorative layer. Solid ingredient of the mixture
does not substantially permeate the sheet. For example, the air-permeable protective
sheet has air-permeability less than Gale permeability of 2000 sec/100cc, preferably
1 to 1000 sec/100cc and comprises synthesized papers which have no impermeable part
of more than 3 mmΦ□preferably 2 mmΦ over the whole surface.
[0047] In this invention, the term "sheet" is not definitely distinguished from "film" in
thickness. If it provides strength enough to form a protective sheet, its thickness
is not especially limited.
[0048] The air-permeable protective sheets include non-water-permeable but air-permeable
sheet in which micropores are formed to apply only air-permeability by known means
such as a needle punch and drawing to non-water-permeable sheets which comprises membrane-like
materials such as polyethylene and polypropylene and water-proof sheets. Other air-permeable
protective sheets are fiber sheets of woven and non-woven fabrics which comprise artificial
fibers such as polyethylene, polypropylene, polyester, vinylon, polyethylene terephtalate
and alkali-resistant glass.
[0049] Preferably, the air-permeable protective sheets may be non-water-permeable sheets
in which micropores are formed to apply air permeability to films such as polyethylene
and polypropylene and air-permeable non-woven fabrics such as polyethylene, polypropylene,
polyester, vinylon and polyethylene terephtalate.
[0050] The air-permeable protective sheets are laminated on the surface of the decorative
layer at suitable peel strength as mentioned above, and during handling the decorative
sheets, the air-permeable protective sheets can be handled without peeling the air-permeable
protective sheets off the decorative layer, and after attachment, the air-permeable
protective sheets can be easily peeled off without involving harmful influence to
the decorative layer.
[0051] The decorative layer obtained by a process as below using the air-permeable sheet
forms a CaCO
3 dense layer on the surface with suitable air-permeability of the air-permeable protective
sheet to have high surface hardness and high scratch resistance even after the air-permeable
protective sheets are removed.
[0052] The air-permeable protective sheet provides excellent bending resistance that makes
a crack difficult to generate even if the decorative sheet is curved, thereby facilitating
handling of the decorative sheet and construction of two-dimensional curved surface.
There is no crack even if the air-permeable protective sheet is removed after constructed
to two-dimensional curved surface, which is advantageous.
[0053] The decorative sheet according to the present invention can be applied with an adhesive
on the surface, and it is preferable to form a known adhesive layer on the surface
of the base sheet of the decorative sheet.
[0054] The method of manufacturing the decorative sheet according to the present invention
is not especially limited, and the following methods are preferable.
[0055] Unhardened slurry of mixture that contains Ca(OH)
3 and water is applied onto the base sheet, and if required, an air-permeable protective
sheet is laminated thereon. While the layer of the mixture is covered with the air-permeable
protective sheet, Ca(OH)
2 in the mixture is carbonated and hardened.
[0056] For Ca(OH)
2, slaked lime, plaster and dolomite plaster that mainly contains Ca(OH)
2 may be used.
[0057] The foregoing additives may be added to the mixture of Ca(OH)
2 and water to provide a suitable ratio, if required.
[0058] Other than the additives, various agents may be added to improve efficiency in manufacturing
of the constructive material. The agents include a thickener, a fluidizing agent and
an antifoamer.
[0059] The thickeners include celluloses such as hydroxy ethyl cellulose and hydroxypropyl
cellulose; polysaccharide that comprises saccharose or glucose; and acryls.
[0060] The fluidizing agents include methyrol/melamine condensates; polycarbonates; melamine
sulfonic formaldehyde condensates; naphthalene sulfonic formaldehyde condensates and
high molecular lignin sulfonic acid.
[0061] The antifoamers include pulronic-type, and polyoxyethylenealkylphenyl ether.
[0062] The addition of the agent is not limited, but the agent may be preferably added as
below.
[0063] The addition of the thickener is variable depending on the function thereof, and
hydroxy ethyl cellulose of 1 % by weight aqueous solution which has viscosity of 100
centi poise at 20 will not have any problem if it is added less than 0.04 % by weight.
[0064] The addition of the fluidizing agent is variable depending on the function of the
fluidizing agent as used. For example, what mainly contains polycarbonate having relatively
separation resistance may be preferably added at 0.1 to 5 % by weight, more preferably
0.5 to 3 % by weight.
[0065] The addition of the antifoamer may be preferably less than 1 % by weight, more preferably
less than 0.3 % by weight.
[0066] Mixture is obtained by mixing Ca(OH)
2 and water that contains the above optional ingredients if required. The mixing ratio
of Ca(OH)
2 and water is not especially limited, but adjusting water contents suitably to provide
viscosity of the mixture to 100 to 40000 centi poise facilitates handling of the production.
To achieve such viscosity, it may be mixed so that the water content may be 20 to
50 % by weight in the mixture.
[0067] To apply the mixture which contains Ca(OH)
2 and water to the base sheet, the mixture is applied to a board by a roll coater,
a flow coater, a knife coater, a comma coater, a spray, dipping, spitting, bar transfer,
and if necessary, molded by trowel pressing, mouth piece contraction, roller pressing
and uniaxial press.
[0068] To cover the surface of the mixture of Ca(OH)
2 and water with the air-permeable protective sheet, there is a method of making closer
to a sheet after molding the layer, or a method of making closer to the air-permeable
protective sheet at the same time with the layer.
[0069] Under the above condition, the mixture of Ca(OH)
2 and water is hardened by allowing the mold of the mixture of Ca(OH)
2 and water to react with CO
2 in air to form CaCO
3. The hardening may be made under the condition that does not prevent carbonization,
and curing time can be shortened by controlling temperature, moisture and CO
2 concentration.
[0070] The curing temperature is 25 to 90 at the beginning, preferably 50 to 80 for 2 to
120 min. to increase yield.
[0071] For hardening, it is important to remove excess water ingredient in the mold of the
mixture and to supply CO
2. As mentioned above, the air-permeable sheet affects evaporation of water to the
outside from the mold of the mixture and supply of CO
2, thereby shortening curing time and increasing surface hardness of the decorative
layer.
[0072] In the method of the present invention, peel strength of the decorative sheet and
air-permeable protective sheet can be suitably adjusted under various conditions.
As effective conditions, there are hydrophilic nature and roughness of the surface
of the air-permeable protective sheet with the decorative sheet; and control of aqueous
emulsion to be added to the mixture and the additive such as silicone oil.
[0073] For example, by increasing hydrophilic nature of the surface of the air-permeable
protective sheet to the decorative layer, peel strength is increased, and on the contrary,
by decreasing hydrophilic nature, peel strength is decreased.
[0074] By increasing additional amount of the aqueous emulsion, peel strength is increased,
and on the contrary, by decreasing the additional amount, peel strength is decreased.
Furthermore, by decreasing addition of silicone oil, peel strength is increased, and
on the contrary, by increasing the additional amount, peel strength is decreased.
ADVANTAGES OF THE INVENTION
[0075] As understood by the above description, the decorative sheet according to the present
invention includes a base sheet having specific thickness and strength, thereby decreasing
elongation by water content of adhesive such as starch used for paste, so that shrinkage
by drying after paste is very little.
[0076] Therefore, adhesion of a plurality of decorative sheets is maintained after drying
to obtain good finishing and to keep a long time stabilty to prevent peeling off after
attachment.
[0077] A stable wall is constructed as mentioned above. Thus, when decorative sheets are
repapered, an additional decorative sheet is attached on the decorative sheet to enable
a stable decorative surface to be formed, and enable very simple construction design
to be taken as never considered in a known decorative sheet.
EXAMPLES OF THE INVENTION AND COMPARATIVE EXAMPLES
[0078] To describe the present invention concretely, embodiments are mentioned, but the
present invention is not limited to the embodiments.
[0079] Tests were carried out in examples and comparative examples by the following process.
[0080] Base sheets used in the tests have tensile strength, water elongation and thickness
as shown in Table 1.
Table 1
Base Sheet |
Base sheet |
Tensile
strength(kN/m) |
Water
elongation(%) |
Thickness
(µ) |
No. |
Paper |
|
|
|
1 |
CaCO3 paper |
1.5 |
1.01 |
130 |
2 |
CaCO3 paper |
3.2 |
0.95 |
130 |
3 |
Single-sided glossy paper |
5.0 |
1.05 |
130 |
4 |
Single-sided glossy paper |
6.8 |
1.04 |
130 |
5 |
Single-sided glossy paper |
7.3 |
1.21 |
130 |
6 |
CaCO3 paper |
1.6 |
0.89 |
150 |
7 |
CaCO3 paper |
3.7 |
0.72 |
150 |
8 |
Single-sided glossy paper |
4.8 |
1.05 |
150 |
9 |
Single-sided glossy paper |
6.7 |
1.02 |
150 |
10 |
Single-sided glossy paper |
7.2 |
0.98 |
150 |
11 |
Single-sided glossy paper |
1.8 |
0.79 |
170 |
12 |
CaCO3 paper |
3.3 |
0.73 |
170 |
13 |
CaCO3 paper |
5.3 |
0.98 |
170 |
14 |
Single-sided glossy paper |
6.9 |
0.89 |
170 |
15 |
Single-sided glossy paper |
7.5 |
1.11 |
170 |
16 |
Ti paper |
2.0 |
1.20 |
100 |
17 |
CaCO3 paper |
4.3 |
1.09 |
100 |
18 |
CaCO3 paper |
3.8 |
1.18 |
110 |
19 |
CaCO3 paper |
3.2 |
1.03 |
120 |
20 |
Single-sided glossy paper |
5.0 |
0.78 |
130 |
21 |
CaCO3 paper |
3.1 |
0.92 |
150 |
22 |
CaCO3 paper |
2.8 |
0.99 |
200 |
23 |
CaCO3 paper |
2.1 |
0.87 |
270 |
24 |
CaCO3 paper |
5.3 |
1.02 |
290 |
25 |
CaCO3 paper |
4.3 |
1.19 |
300 |
26 |
CaCO3 paper |
4.1 |
1.22 |
310 |
27 |
CaCO3 paper |
3.8 |
1.01 |
320 |
28 |
CaCO3 paper |
4.3 |
1.35 |
150 |
29 |
CaCO3 paper |
3.8 |
1.42 |
150 |
[0081] The base sheet Nos.7, 12, 16, 28 and 29 have air-permeability of 7, 6, 20, 7 and
8 sec.
[0082] Onto the surface of the base sheet, mixtures obtained by mixing materials by ratios
in Tables 2 and 3 were applied by a roll coater, and air-permeable protective sheets
were laminated to achieve thickness of 200µm after hardening.
[0083] Table 2 shows examples according to the present invention, and Table 3 shows comparative
examples that are not included in the present invention. The base sheet number in
column 2 of Tables 2 and 3 are the same as those described in Table 1.
Table 2
Examples of the Invention |
Example |
Base sheet
No. |
Air-permeable
Protective sheet |
Thickness of
Decorative layer(µ□) |
1 |
12 |
Unwoven fabric A |
200 |
2 |
7 |
Unwoven fabric B |
200 |
3 |
1 |
Unwoven fabric A |
200 |
4 |
2 |
Unwoven fabric A |
200 |
5 |
3 |
Unwoven fabric A |
200 |
6 |
4 |
Unwoven fabric A |
200 |
7 |
6 |
Unwoven fabric A |
200 |
8 |
7 |
Unwoven fabric A |
200 |
9 |
8 |
Unwoven fabric B |
200 |
10 |
9 |
Unwoven fabric A |
200 |
11 |
11 |
Unwoven fabric A |
200 |
12 |
12 |
Unwoven fabric A |
200 |
13 |
13 |
Unwoven fabric A |
200 |
14 |
14 |
Unwoven fabric A |
200 |
15 |
19 |
Unwoven fabric A |
200 |
16 |
20 |
Unwoven fabric A |
200 |
17 |
21 |
Unwoven fabric A |
200 |
18 |
22 |
Unwoven fabric A |
200 |
19 |
23 |
Unwoven fabric A |
200 |
20 |
24 |
Unwoven fabric A |
200 |
21 |
25 |
Unwoven fabric A |
200 |
22 |
28 |
Unwoven fabric A |
200 |
23 |
29 |
Unwoven fabric A |
200 |
24 |
12 |
Unwoven fabric A |
700 |
Table 3
Comparative Examples |
Comparative Example |
Base sheet No. |
Air-permeable protective sheet |
Thickness of decorative layer
(µ□) |
1 |
5 |
Unwoven fabric A |
200 |
2 |
10 |
Unwoven fabric A |
200 |
3 |
15 |
Unwoven fabric A |
200 |
4 |
16 |
Unwoven fabric A |
200 |
5 |
17 |
Unwoven fabric A |
200 |
6 |
18 |
Unwoven fabric A |
200 |
7 |
26 |
Unwoven fabric A |
200 |
8 |
27 |
Unwoven fabric A |
200 |
"Unwoven fabric A and B" are BT-1306WM by Unisel Co., Ltd. and Tybeck 1059B by Asahi
DuPont Flashpsan Products Co., Ltd. respectively.
[0084] In all Examples of the invention and Comparative Examples except Examples 1, 2 and
8, the mixture contains 100 parts by weight of Ca(OH)
2, 60 parts by weight of inorganic thin bone material, 60 parts by weight of aqueous
emulsion, 6 parts by weight of fluidizing agent and 16 parts by weight of water. Ca(OH)
2 is high purity slaked lime by Ube Material; inorganic thin bone material is "Ecal
100" by Iida Mfg., Co., Ltd.; aqueous emulsion is "Polytron A1480" by Asahi Kasei
Industries, Ltd.; fluidizing agent is "Seacament 1000NT" by Nihon Seaca Co., Ltd.
[0085] Example 1 comprises 100 parts by weight of Ca(OH)
2 which is "Yukijirushi Sakanyo" by Tanaka Lime Industries, Ltd.; 60 parts by weight
of inorganic thin bone material which is "Ecal 100" by Iida Mfg., Co., Ltd.; 60 parts
by weight of aqueous emulsion which is "Mobinil 60" by Hexist Synthesis Co., Ltd.
that comprises acryl styrene copolymer having 47 % by weight of solid ingredient.;
6 parts by weight of fludizing agent "Leobild SP-8N" by Pozolis Bussan Co., Ltd. Example
2 comprises 100 parts by . weight of Ca(OH)
2 which is JIS R 9001-81; 60 parts by weight of inorganic thin bone material which
is "White 7" by Yakuzen Lime; 70 parts by weight of aqueous emulsion which is "Polytron
A1480" by Asahi Kasei Industries, Ltd.; 6 parts by weight of fluidizing agent is "Seacament
1000NT" by Nihon Seaca Co., Ltd. and 10 parts by weight of water. Example 8 is the
same as Examples 3 to 7 and 9 to 24 except the inorganic thin bone material which
is "White 7" by Yakuzen Lime.
Test Procedures
[0086] The sample was dried for five minutes at 80 , and the mixture was hardened to form
a decorative layer which contains CaCO
3 as bonding ingredient.
As shown in Figure, a decorative sheet thus obtained comprises a base sheet 1 and
a decorative layer 2. A air-permeable protective sheet 3 is laminated on the surface
of the decorative layer.
[0087] The air-permeable protective sheet 3 of the decorative sheet can be easily peeled
off by pulling it by hand without breaking the decorative layer.
[0088] The decorative sheet thus obtained was left under the condition of relative humidity
of 65 % at 25 so that carbonation rate or change rate from Ca(OH)
2 to CaCO
3 may be more than 75 %. Test results of the decorative sheet thus obtained are shown
in Tables 4 and 5.
[0089] The following tests were carried out.
(1) Peel strength test by repeating drying and moisturizing
[0090] The base sheet surface of a decorative sheet was pasted onto the whole surface of
150×300 mm transite, and a air-permeable protective sheet was peeled off. It was dried
for 24 hours and a sample was obtained.
[0091] The obtained sample was moisturized for two hours in steam of temperature of 60 and
humidity of 95 %. It was repeated 30 times that it was dried for two hours in a hot-air
dryer of 60 . As a result of the test, the sample around which a twisted portion was
not found was determined as " ", and the sample around which it was found was determined
as "×".
(2) Compulsory gap test
[0092] On the surface of 900×900 mm gypsum board, two decorative sheets which has 450×900
mm was pasted by a wall paper adhesive which is "Roormild" by Yayoi Chemical Industries
Co., Ltd. without space, and the air-permeable protective sheet was peeled off to
provide a sample.
[0093] The obtained sample was put into a hot-air dryer of 60 at once and stored for three
hours. A gap in a seam was observed and determined by a microscope.
(3) Opacifying property test of ground projections
[0094] A tack seal which has diameter of 30 mm and thickness of 0.1 mm was pasted on the
middle portion of a gypsum board of 300×300 ×12 mm. The base sheet surface of the
decorative sheet was pasted on the whole surface of the gypsum board by a wall paper
adhesive which is "Roormild" by Yayoi Chemical Industries Co., Ltd. and the air-permeable
protective sheet was peeled off.
[0095] Thereafter, the surface of the decorative sheet was observed under natural light,
and the tack seal on which a projection was not found was determined as " ", and the
tack seal on which a projection was found was determined as "×".
[0096] Table 4 shows results of the above tests (1), (2) and (3) carried out with respect
to Examples according to the present invention, and Table 5 shows results of the above
tests (1), (2) and (3) carried out with respect to Comparative Examples that are not
included in the present invention.
Table 4
Test Results |
(Examples of the invention) |
Example |
Test results |
|
Peel strength
(1) |
Gap (mm)
(2) |
Opacifying
properties(3) |
1 |
|
0 |
|
2 |
|
0.01 |
|
3 |
|
0.01 |
|
4 |
|
0 |
|
5 |
|
0.01 |
|
6 |
|
0.03 |
|
7 |
|
0.01 |
|
8 |
|
0.01 |
|
9 |
|
0.01 |
|
10 |
|
0.03 |
|
11 |
|
0.01 |
|
12 |
|
0 |
|
13 |
|
0.02 |
|
14 |
|
0.03 |
|
15 |
|
0.01 |
|
16 |
|
0.01 |
|
17 |
|
0.01 |
|
18 |
|
0.02 |
|
19 |
|
0.01 |
|
20 |
|
0.02 |
|
21 |
|
0.01 |
|
22 |
|
0.01 |
|
23 |
|
0.01 |
|
24 |
|
0 |
|
Table 5
Test Results |
(Comparative Examples) |
Comparative Example |
Test results |
|
Peel strength
(1) |
Gap (mm)
(2) |
Opacifying
properties(3) |
1 |
× |
0.05 |
|
2 |
× |
0.06 |
|
3 |
× |
0.06 |
|
4 |
|
0.01 |
× |
5 |
|
0.01 |
× |
6 |
|
0 |
× |
7 |
|
0.03 |
|
8 |
|
0.03 |
|
[0097] When the gap exceeded 0.05 mm, a joint was observed to involve poor appearance.
[0098] In Comparative Examples 7 and 8 in which thickness of the base sheet exceeded 300
µ, the results were not so poor as shown in Table 5. But it is likely to collapse
in thickness direction. When the surface of the decorative sheet was pressed by a
finger, a crack was observed on the decorative layer. Comparative Examples 7 and 8
are found to be unsuitable as decorative sheet.
[0099] From the above, Examples of the present invention achieved good results, and Comparative
Examples did not achieve good results.
[0100] From the foregoing results, it was proved that what has a base sheet having thickness
of 120 to 300 µm and tensile strength of 1.5 to 7 kN was suitable as decorative sheet.
[0101] The foregoing merely relate to embodiments of the present invention. Various changes
and modifications may be made by persons skilled in the art without departing from
the scope of claims wherein: